CN101237470B - A car ground broadband access method based on wireless multi-hop network technology - Google Patents
A car ground broadband access method based on wireless multi-hop network technology Download PDFInfo
- Publication number
- CN101237470B CN101237470B CN2008100449481A CN200810044948A CN101237470B CN 101237470 B CN101237470 B CN 101237470B CN 2008100449481 A CN2008100449481 A CN 2008100449481A CN 200810044948 A CN200810044948 A CN 200810044948A CN 101237470 B CN101237470 B CN 101237470B
- Authority
- CN
- China
- Prior art keywords
- node
- wireless multi
- hop
- frame
- layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Mobile Radio Communication Systems (AREA)
Abstract
The invention discloses a vehicle-ground broadband access method based on a wireless mesh network technology, in which an access method for wireless mesh points consist of gateway nodes and a plurality of access points is specified in a layer 2 address-based layer 2.5 protocol between a layer 2 protocol and a layer 3 protocol. The method comprises the following steps: a, creating and updating a tree-based routing table for each wireless mesh point, which is used for recoding physical addresses for a parent node and a child node, and creating and updating a proxy table for each wireless mesh point, which comprises table entries of all vehicle-carried subnet point below the tree-based routing table of the wireless mesh point; b, data frame transmission, which realizes data format conversion, data transmission, data receiving and forwarding between a wireless mesh network and a vehicle-carried subnet as well as between wireless mesh gating nodes and a public network through the wireless mesh points; c, node switch, in which channels of the same frequency are adopted for access channels of all wireless mesh point for realizing seamless switching between the nodes. The method has the advantages of convenient networking, low cost, high-speed for data transmission, high reliability.
Description
Technical field
The present invention relates to the data transmission technology of wireless network, particularly a kind of car ground broadband access method based on wireless multi-hop network technology.
Background technology
Along with vehicle-carried mobile users such as railway, highway continuous increase to public information network access demand in the travelling process, the support level that existing information network inserts the vehicle-carried mobile user has been difficult to satisfy user's demand.Particularly along with the starting in succession of high speed passenger vehicles and luxury travel vehicle, the mobile access technology of information network must be improved accordingly.
Wireless multi-hop network is a kind of novel broadband wireless network structure, the distributed network of promptly a kind of high power capacity, two-forty.On network topology, wireless multi-hop network comprises mobile Ad hoc (wireless Ad Hoc) network, Wireless Mesh (netted) network (WMN) etc.; On single-hop inserts, wireless multi-hop network can regard as a kind of special WLAN (Wireless Local Area Network, WLAN).Because higher reliability, bigger retractility and lower cost of investment are arranged, and wireless multi-hop network begins to be paid attention to especially and use.Through literature search, we find for car ground broadband wireless access method and system, still not have any complete technical scheme; And, through new patent searching, do not find total solution based on the car ground broadband access system of wireless multi-hop network yet.
Current, formulate by IEEE is leading based on WMN (wireless mesh network) standard of WLAN (WLAN) basic fundamental, be called IEEE 802.11s standard.The front page standard still among formulating, supplies each discussion of the standard unit of participating and draw and modification but IEEE has formulated front page IEEE 802.11s draft standard.
Press IEEE 802.11s draft, the WMN network topology structure is divided into 3 layers, and minimum one deck topological layer is " terminal use's layer ", is made up of subscriber terminal equipment, comprises equipment such as mobile phone, notebook computer, PDA, formation standard 802.11 Access Networks; Topological layer on " terminal use's layer " is " Wireless Mesh (grid) layer "; Wireless Mesh node (Mesh Point by pure forwarding; MP) and can transmit the Wireless Mesh access node that also can insert (Mesh Access Point MAP) constitutes, and forms WMN; The terminal use can insert core network through this layer, also can carry out data interaction through this layer between the terminal use; The 3rd topological layer of WMN is " a core network layer ", and the diverse network interconnect service mainly is provided.
The main network element of WMN solution be the Wireless Mesh node (Mesh Point, MP) and wireless mesh access point (Mesh Access Point MAP) constitutes, and each network element major function is following:
Wireless mesh access point (Mesh Access Point, MAP).The function that at first has traditional access point, when terminal use's access network, equally must be through the scheduling access network of physical layer transmission, IEEE 802.11 or IEEE 802.11e MAC layer.The fundamental difference of MAP and traditional WLAN access point (AccessPoint) AP is that MAP has routing mechanism.If not the user in the single-hop scope if need intercommunication mutually, must search the path that arrives destination node by source node through routing mechanism, comes Data transmission according to this routing information then, then there is not routing function in traditional AP.
The Wireless Mesh node (Mesh Point, MP).The major function of Wireless Mesh node is to connect WMN and core network, makes the terminal equipment that wireless network card is housed can share the resource of core net through MAP.
IEEE 802.11s draft standard is the good solution of wireless multi-hop network; But be not to formulate to car ground broadband access system specially; Therefore in the shortcoming of using below also existing: 1), adopt common latticed IEEE802.11s scheme efficient lower for car ground broadband access system special straight line or tree type route topological structure; 2) IEEE 802.11s draft does not define quick seamless switching, and must break off the back when broadband, car ground roaming inserts earlier, insert new node again, and consuming time longer, network is connected interrupt, can't satisfy the requirement of car ground broadband access system continuous wide band access.
The IP speech provide a kind of in IP network the method for transport voice packets, rely on wireless wideband access network, cheap, abundant, personal radio communication service flexibly can be provided.
For the IP voice service, crucial is QoS guarantee method (QoS) demand that will satisfy it, otherwise just can't carry out effective Speech Communication.But the result of study of numerous documents shows, based on the wireless multi-hop network of IEEE 802.11, because its bottom adopts the MAC agreement of type DCF, can't satisfy the QoS demand of the desired low time delay of IP voice service, low delay variation, low packet loss ratio.Find through the paper and the Searches of Patent Literature; The QoS scheme of the IP voice service that is proposed in existing paper or the patent; All be to suppose to know and send type of service from upper network layer; Common way is when carrying out emulation, and specifying some Frame professional is the IP voice service, and other packet is a Best-Effort service.To classify to business with grader though some paper has been mentioned, not propose concrete method, particularly can be applied in the method in the real system.
Summary of the invention
The object of the invention just provides a kind of car ground broadband access method based on wireless multi-hop network technology, and this method networking is convenient, cost is low, data transmission bauds is high, good reliability.
The present invention realizes that the technical scheme that above-mentioned purpose adopts is: a kind of car ground broadband access method based on wireless multi-hop network technology, by the radio node of vehicle-mounted subnet, insert public internet network again through wireless multi-hop networks; Wherein wireless multi-hop networks is made up of a plurality of wireless multi-hop nodes, and the wireless multi-hop node is gateway node or access node, and access node has a plurality of, and the employed protocol stack of wireless multi-hop networks has the 1st, 2 layer IEEE 802.11g agreement, the 3rd layer IP agreement.And between the 2nd, 3 layer protocols, also have the 2.5th layer protocol based on layer 2 address, the 2.5th layer protocol has been stipulated the cut-in method of wireless multi-hop node, and this cut-in method is made up of following steps:
A, each wireless multi-hop node generate or upgrade the routing table of tree type, write down the father of this wireless multi-hop node, the physical address of child node; And the establishment proxy table, this proxy table comprises the list item of all the vehicle-mounted subnet nodes below this node tree type route, and each list item is made up of the physical address of the physical address of this node, vehicle-mounted subnet node that this node is acted on behalf of; The physical address of the vehicle-mounted subnet node of perhaps being acted on behalf of by the physical address of the child node of this node, this child node and with lower node is formed.
The transmission of B, Frame: the wireless multi-hop node combines the inquiry of proxy table, routing table simultaneously through routing algorithm; Confirm routed path; Call transmission, reception, retransmission process again, realize between the wireless multi-hop node, the data between wireless multi-hop networks and the vehicle-mounted subnet, between wireless multi-hop gateway node and the public internet send, receive and forwarding; And between wireless multi-hop networks and vehicle-mounted subnet, between wireless multi-hop gateway node and the public internet, carry out format conversion during the transmission data.
The switching of C, node: the access channel of all wireless multi-hop nodes all adopts the channel of same frequency; Vehicle-mounted subnet node is surveyed the reception signal strength signal intensity of other wireless multi-hop nodes at any time; When the received power value of the wireless multi-hop node that is using is lower than predetermined threshold value; And when the received power value that detects new wireless multi-hop node is higher than this threshold value, when keeping old connection, initiate connection request to new access point; After requested node is received request signal, the update agent table, foundation is connected with this vehicle-mounted subnet, and vehicle-mounted then subnet request is broken off and being connected, and breaks off it by old node and connects also update agent table.
Compared with prior art, the invention has the beneficial effects as follows:
One, the present invention adopts the routing table of each node only to write down his father, child node; Make whole wireless multi-hop network constitute tree type route topological structure; The root node (wireless gateway node) of tree type route is arranged on the central hub position of railway, highway, and the radio node of the last position of topological structure is arranged on the concentrated intersection of railway, highway flow; The terminal radio node of topological structure be arranged on railway, highway along the line everywhere; Make the actual distribution structure of tree topology of the present invention and railway, highway adaptive fully, the flow direction of information requirement realizes the consistent of maximum possible with the path of Route Selection.Therefore, information transfer efficiency of the present invention is high, and networking is convenient, cost is low.Simultaneously, routing table only writes down his father, child node, and proxy table record oneself and vehicle-mounted subnet node address below the child node make each node in transfer of data and the access procedure only need and oneself father, child node generation exchanges data, have improved efficiency of transmission.
Two, node that writes down in routing table and the proxy table and vehicle-mounted node address adopt two layer MAC address (hardware address of node and vehicle-mounted node); MAC Address is independently to be present in two layers; Unique in the global range, and do not rely on the IP address in three layers of Routing Protocol of tradition.So when in extremely complicated wireless network environment, seeking route, it has stronger adaptive faculty, better the variation of reaction network environment.
Three, in traditional internet; The forwarding of data function is all realized by the 3rd layer (being the IP layer); And transfer of data of the present invention is based on 2.5 layers of transmission of two layer MAC address; Have tangible advantage with respect to three layers of forwarding: because packet transmits through two layers, so protocol stack reduces its fractionation and encapsulation number of times, the time that packet stops in protocol stack also correspondingly reduces; So just brought shorter transmission delay, more can satisfy some service quality guarantee requirements delay sensitive professional (like the IP voice service).In addition, similar with two layers of bridge, 2.5 layers of forwarding capability are transparent to the upper strata, so just can avoid owing to lower-layer protocols changes the influence to upper-layer protocol that causes, thereby increase the stability of system.
Four, the access channel of all wireless multi-hop nodes (gateway node, access node) all adopts identical frequency; Vehicle-mounted subnet node is that terminal node is before switching; The channel scan procedure of can not need carry out length consuming time just can be surveyed the reception signal strength signal intensity of other access points at any time, and when keeping old connection, initiate to connect to new access point on the channel that terminal node is using; The physical connection of having avoided the detection to all physical channels to cause is interrupted, and realizes complete seamless switching.
The above-mentioned concrete grammar that between wireless multi-hop networks and vehicle-mounted subnet, between wireless multi-hop gateway node and the public internet, carries out format conversion during the transmission data is: between the Frame frame head of second layer Frame frame head and the 3rd layer, add the 2.5th layer wireless multi-hop frame head, each field of this wireless multi-hop frame head is followed successively by: next jumps physical address, last a jumping physical address, target physical address, source physical address, wireless multi-hop frame type field, business type field in the Frame.
Through such format conversion, the present invention can realize between wireless multi-hop networks and the vehicle-mounted subnet reliably, the transfer of data between wireless multi-hop gateway node and the public internet.And, only need 4 MAC Addresss (a last jumping address, next hop address, destination address, source address) both can accomplish data forwarding in the frame head of wireless multi-hop data frame, make its transfer of data efficient, reliable.
The addressing method of the transmission of above-mentioned Frame is:
Addressing when sending data: when sending data, at first search proxy table,, then Frame is sent to wireless multi-hop node processing corresponding in the proxy table if there is the physical address of the vehicle-mounted node of purpose in the proxy table; If do not exist, then send to father node and handle.
Addressing when reception and forwarding data: after receiving data, search routing table, if there is not a last jumping address of this Frame in the routing table, then confirm it is not the Frame that own father node and child node are sent, this Frame abandons; If receive the Ethernet broadcast data frame, then handle by the layer 3 network agreement, and send to all nodes of removing in the routing table beyond the broadcast data frame source node simultaneously by this node; If receive the Ethernet unicast data frames, search proxy table, if self be the agent node of this Frame Ethernet destination address; Then handle by the layer 3 network agreement by this node; Otherwise, carrying out forwarding of data, the addressing method of data forwarding is identical with the transmission Frame.
The mode that more than adopts two layers of routing table and proxy table to combine realizes data forwarding and mac addressing mechanism, makes the handling procedure of each node transmission data simply efficient.Simultaneously effective tree type routing infrastructure makes the path optimization of transfer of data, has improved data transmission efficiency on the whole.In addition, owing to when transmitting broadcast data frame, do not transmit, thereby avoided the generation of broadcast storm in the wireless multi-hop networks fully, further improved the stability of system to the broadcast data frame source node.
Above-mentioned wireless multi-hop agreement also comprises two layers of IP voice service method for guaranteeing quality, and this method may further comprise the steps:
At the access node or the gateway node of wireless multi-hop network, Frame is discerned and the IP voice data frame that identifies is carried out mark, promptly in the business type field of the wireless multi-hop frame head of Frame, be recorded as speech; In the repeating process of Frame, the preferential forwarding has the voice data frame.
The present invention has set up and a kind ofly the ip voice Frame has been discerned the method for mark at two layer MAC address like this.Thereby can take strategy to carry out special treatment to the IP voice service in the actual system, to satisfy the demand of its voice service quality assurance.
The method of above-mentioned identification voice data frame is:
A1, two layers of IP speech signaling are caught: from Frame, obtain to set up or remove the signaling that the IP speech connects period.
A2, IP speech signaling resolve, as the signaling that is resolved to be the signaling that connects, and connection IP address, transport layer port information with the IP speech of acquisition deposit IP speech link information storehouse in; As the signaling that is resolved to is for removing signaling, then with corresponding connection IP address, transport layer port information deletion in the link information storehouse.
A3, the recognition methods of IP voice service; Information in purpose IP address in the IP frame head in the Frame frame head that on two layers, all is passed through and the destination interface in the transport layer frame head and the IP speech link information storehouse compares; If have this IP address and corresponding port in the information bank, then this Frame be labeled as the voice data frame.
Like this, the invention solves the key issue of on 2.5 layers, the ip voice business being discerned, can identify the IP voice data frame of transmission accurately, simply, make it in practical application, voice be implemented in the priority treatment in the repeating process.Make that ip voice is clear, continuous, short time delay, satisfy the quality of service requirement of ip voice communication.Make the car ground broadband access method of wireless multi-hop network technology proposed by the invention be applicable to that more car ground inserts the scene that such voice service accounts for very big proportion, especially significant to the safety of railway, highway transportation.
The concrete grammar that above-mentioned two layers of IP speech signaling are caught is:
All Frames are made a copy, from copy, take out the IP frame head of Frame and the transport layer header of transport layer, obtain wherein source IP address, purpose IP address, source port, destination interface; And confirm that according to this its type of message is: H.225 authentication registration state (RAS) message of agreement, call-signaling message H.225, H.245 control a kind of in signaling message, conversation initialized protocol (SIP) protocol message; According to the type of message that obtains, call the IP speech signaling analytic method in the A2 step; Otherwise abandon this Frame copy.
Like this, this method is resolved through the copy that obtains the Frame copy, rather than Frame itself is resolved, and does not influence the Frame normal transmission, has guaranteed the efficient of transfer of data.
The concrete practice that IP speech signaling is resolved in the above-mentioned A2 step is:
H.225 authentication registration state (RAS) message of agreement is decoded with ASN.1 (coding standard) decoder; To H.225 call-signaling message or H.245 control the signaling that the connection in the signaling message sets up and remove and decode with ASN.1 coding standard decoder; Signaling to the connection of conversation initialized protocol (SIP) protocol message is set up and removed is decoded with the text protocol decoder.
Like this, this method is only taked containing the mode that the signaling of setting up the ip voice link information is resolved, rather than all ip voices are resolved, and has simplified the parsing complexity, has improved analyzing efficiency.
Above-mentioned IP speech link information storehouse comprises following three information tables: authentication registration state (RAS) link information table H.225, and each list item of this table comprises the IP address and the transport layer port of an authentication registration state (RAS) transmission channel; H.225 call signaling link information table, each list item of this table comprises the IP address and the transport layer port of a call signaling transmission channel; Speech Communication link information table, each list item of this table comprises the IP address and the transport layer port of the transmission that the Speech Communication agreement of an IP speech and video communication is used.
Like this, be divided into several tables, make the clear in structure, clear of information bank through the information that connects ip voice, convenient signaling catch and the identification of IP Speech frame in the inquiry contrast, also improved the efficient of contrast.
Below in conjunction with accompanying drawing and concrete execution mode the present invention is done further detailed description.
Description of drawings
The wireless multi-hop network structural representation that Fig. 1 makes up for embodiment of the invention cut-in method.
Fig. 2 is the sketch map of embodiment of the invention cut-in method.
Fig. 3 is a wireless multi-hop protocol layer frame structure in the embodiment of the invention.
Fig. 4 is a wireless multi-hop protocol layer frame frame head structure in the embodiment of the invention
Fig. 5 is that the vehicle-mounted subnet node of the embodiment of the invention sends data structure diagram.
Embodiment
Embodiment
Fig. 1,2 illustrates, and a kind of car ground broadband access method based on wireless multi-hop network technology is by the radio node of vehicle-mounted subnet, insert public internet network through wireless multi-hop networks again; Wherein wireless multi-hop networks is made up of a plurality of wireless multi-hop nodes, and the wireless multi-hop node is gateway node Portal or access node MAP, and access node MAP has a plurality of, like MAP1, MAP2, MAP3.The employed protocol stack of wireless multi-hop networks has the 1st, 2 layer IEEE 802.11g agreement, the 3rd layer IP agreement.And 2nd, also have the 2.5th layer protocol based on layer 2 address between 3 layer protocols, the 2.5th layer protocol has been stipulated the cut-in method of wireless multi-hop node.This cut-in method is made up of following steps:
A, each wireless multi-hop node generate or upgrade the routing table of tree type, write down the father of this wireless multi-hop node, the physical address of child node; And the establishment proxy table, this proxy table comprises the list item of all the vehicle-mounted subnet nodes below this node tree type route, and each list item is made up of the physical address of the vehicle-mounted subnet node STA that physical address, this node of this node are acted on behalf of; The physical address of the vehicle-mounted subnet node STA that is perhaps acted on behalf of by the physical address of the child node of this node, this child node and with lower node is formed.
The transmission of B, Frame: the wireless multi-hop node combines the inquiry of proxy table, routing table simultaneously through routing algorithm; Confirm routed path; Call transmission, reception, retransmission process again, realize between the wireless multi-hop node, the data between wireless multi-hop networks and the vehicle-mounted subnet, between wireless multi-hop gateway node Portal and the public internet send, receive and forwarding; And between wireless multi-hop networks and vehicle-mounted subnet, between wireless multi-hop gateway node Portal and the public internet, carry out format conversion during the transmission data.The method of format conversion belongs to the data frame transfer Data Control module in the 2.5 layer protocol stacks.
Fig. 2,3 illustrates, and the concrete grammar that this example is carried out format conversion according to the data frame transfer Data Control module in the 2.5 layer protocol stacks is: the wireless multi-hop frame head that between second layer Frame frame head (this frame head is confirmed by IEEE 802.11g MAC module) and the 3rd layer data frame frame head (I P packet header), adds the 2.5th layer; Fig. 4 then illustrates, and each field of this wireless multi-hop frame head is followed successively by: next is jumped physical address, last and jumps physical address, target physical address, source physical address, wireless multi-hop frame type field, business type field in the Frame.
Addressing method during this routine data frame transfer: the addressing when sending data: when sending data, at first search proxy table,, then Frame is sent to wireless multi-hop node processing corresponding in the proxy table if there is the physical address of the vehicle-mounted node of purpose in the proxy table; If do not exist, then send to father node and handle.Addressing when reception and forwarding data: after receiving data, search routing table, if there is not a last jumping address of this Frame in the routing table, then confirm it is not the Frame that own father node and child node are sent, this Frame abandons; If receive the Ethernet broadcast data frame, then handle by the layer 3 network agreement, and send to all nodes of removing in the routing table beyond the broadcast data frame source node simultaneously by this node; If receive the Ethernet unicast data frames, search proxy table, if self be the access node of acting on behalf of of this Frame Ethernet destination address; Then handle by the layer 3 network agreement by this node; Otherwise, carrying out forwarding of data, the addressing method of data forwarding is identical with the transmission Frame.
The switching of C, node: the access channel of all wireless multi-hop nodes all adopts the channel of same frequency; Vehicle-mounted subnet node is surveyed the reception signal strength signal intensity of other wireless multi-hop nodes at any time; When the received power value of the wireless multi-hop node that is using is lower than predetermined threshold value; And when the received power value that detects new wireless multi-hop node is higher than predetermined threshold value, when keeping old connection, initiate connection request to new access point; Requested node is received request signal, the update agent table, and foundation is connected with this vehicle-mounted subnet, and vehicle-mounted then subnet request is broken off and being connected, and breaks off it by old node and connects update agent table.Step and method that these nodes switch belong to the handover module in the 2.5 layer protocol stacks, and be as shown in Figure 2.
The generation of this routine routing table and the method for maintenance are: at first will select for use a gateway node Portal as root node in one network, tree topology comes main being responsible for to set up and safeguard by root node Portal.Root node Portal can periodically initiate root broadcast announcement signal, the root status of all the other node declarations in network oneself.The non-root node that can receive broadcast of close together is wireless multi-hop access node MAP; Receive that a last hop node of the broadcast singal of at first oneself receiving behind the root broadcast singal is set to the father node of oneself; And then to father node initiation child node registration message, the root notification message that will receive is at last transmitted and is broadcasted away.Receive the node of this broadcasting,, then become the child node of a last hop node of transmitting broadcasting, go down so repeatedly, just can in whole network, set up tree-like route topological quickly if do not receive broadcasting before.And after the father and son shows to set up completion; In the cycle of new root broadcast; Each node all can further safeguard the set membership table of oneself according to the message of receiving, such as: father node that the child node that deletion was lost efficacy, the new child node that increases, replacement were lost efficacy or the like.
Fig. 5 illustrates, and utilizes the inventive method from the concrete addressing instance that a vehicle-mounted subnet node STA1 sends data to another vehicle-mounted subnet node STA2, mainly comprises following step:
1, the data of STA1 transmission get into wireless multi-hop networks inside by the wireless multi-hop access node MAP1 of its access; MAP1 at first searches proxy table; Find that destination address STA2 is not present in his agency in the list item, therefore data are passed to his father node-wireless multi-hop gateway node Portal.
2, after the Portal node is received the Frame of MAP1 node transmission, search proxy table, find that destination address STA2 is present in his agency in the list item, agency's child node is MAP2, so Frame is sent to access node MAP2.
3, in like manner, MAP2 finds that destination address STA2 is present in his agency in the list item, and agency's child node is the 3rd access node MAP3, so Frame is sent to the 3rd access node MAP3.
4, MAP3 searches proxy table after receiving data, finds that STA2 is oneself agency, then sends to STA2 with data.
This routine wireless multi-hop agreement also comprises two layers of speech (IP speech) QoS guarantee method, and this method may further comprise the steps:
At the access or the gateway node of wireless multi-hop network, Frame is discerned and speech (IP speech) Frame that identifies is carried out mark, promptly in the business type field of the wireless multi-hop frame head of Frame, be recorded as speech; In the repeating process of Frame, the preferential forwarding has the voice data frame.
The method of the identification voice data frame that this is routine is:
A1, two layers of IP speech signaling are caught: from Frame, obtain to set up or remove the signaling that the IP speech connects period; Concrete grammar is: all Frames are made a copy, from copy, take out the IP frame head of Frame and the transport layer header of transport layer, obtain wherein source IP address, purpose IP address, source port, destination interface.And determine whether it is a kind of in the following type of message: H.225 authentication registration state (RAS) message of agreement, call signaling H.225 (Call Signaling) message, H.245 control signaling message, conversation initialized protocol (SIP) protocol message; If then carry out IP speech signaling and resolve; Otherwise, abandon this Frame copy.
A2, IP speech signaling resolve, as the signaling that is resolved to be the signaling that connects, and connection IP address, transport layer port information with the IP speech of acquisition deposit IP speech link information storehouse in; As the signaling that is resolved to is for removing signaling, then with corresponding connection IP address, transport layer port information deletion in the link information storehouse;
The concrete grammar that parsing obtains connecting IP address, transport layer port is:
H.225 authentication registration state (RAS) message of agreement is decoded with ASN.1 coding standard decoder.The type that decoding obtains is the GRQ (gatekeeper's request) of RAS message, and GCF (gatekeeper's affirmation) message obtains the IP address and the transport layer port of the RAS channel in the message, and upgrades the part of the RAS channel information in the IP speech link information storehouse; If type is the ARQ (authentication request) in the RAS message; ACF (authenticate-acknowledge) message; Obtain the IP address and the transport layer port of call signaling (Call Signaling) channel in the message, and upgrade the part of call signaling (Call Signaling) information in the IP speech link information storehouse.
To H.225 Call Signaling message or H.245 control the signaling that the connection in the signaling message sets up and remove and decode with ASN.1 coding standard decoder; If decoded result comprises the H.245 information of channel, then upgrade the part of the H.245 channel information in the IP speech link information storehouse; If wherein comprise FastStart (fast initialization conversation element) message, obtain the IP address and the transport layer port of the transmission of Speech Communication wherein, and upgrade in the IP speech link information storehouse part about the Speech Communication transmitting channel information.
Signaling to the connection of conversation initialized protocol (SIP) protocol message is set up and removed is decoded with the text protocol decoder.The type of message that decoding obtains is INVITE (session invitation) message of SIP; The IP address that then from CONNECT (connection) field wherein, obtains transmitting; From MEDIA (medium) field wherein, obtain the Speech Communication transmit port of voice channel; From VEDIO (video) field wherein, obtain the Speech Communication transmit port of video channel, upgrade the part in the IP speech link information storehouse then about the Speech Communication transmitting channel information.
The IP speech link information storehouse that this is routine comprises following information table:
H.225RAS link information table, each list item of this table comprises the IP address and the transport layer port of a RAS transmission channel; H.225 Call Signaling (call signaling) link information table, each list item of this table comprises the IP address and the transport layer port of a Call Signaling (call signaling) transmission channel; Speech Communication link information table, each list item of this table comprises the IP address and the transport layer port of the transmission that the Speech Communication agreement of an IP speech and video communication is used.
A3, the recognition methods of IP voice service: the information in purpose IP address in the IP frame head in the Frame frame head that on two layers, all is passed through and the destination interface in the transport layer frame head and the IP speech link information storehouse compares; If have this IP address and corresponding port in the information bank, then this Frame be labeled as the voice data frame.
Below provide the details of ip voice communication and service quality guarantee instantiation thereof:
H.323 (comprise H.225, H.245 agreement) IP speech is installed on the gateway node Portal closes and keeps server.H.323 agreement comprise H.225, agreement H.245.It is that IP speech client provides authentication registration and is connected the service of foundation that server is kept in IP speech pass.In this example, we suppose that also except an IP Speech Communication connected, remaining bandwidth was all taken by other business between vehicle-mounted subnet node STA and the gateway node Portal, and promptly network is in a kind of state of heavy-duty service.
Typical signalling interactive process based on the IP speech voice communication of agreement H.323 (comprise H.225, H.245 agreement).An onboard wireless subnet node STA1, initiate the IP voice call, and finish this communication process by STA1 through gateway node Portal (promptly not by gateway node Portal agency) another vehicle-mounted node STA2 outside gateway node Portal:
In communication at first, STA1 keeps the pass in the gateway node Portal that it is registered server and sends calling access request (ARQ), has wherein comprised the destination address STA2 that calls out.The pass is kept server and is replied an authenticate-acknowledge calling access response message (ACF) to STA1, has wherein comprised the transport layer port address 1720 of H.225 calling out control channel of STA2.
This moment, the agent node MAP1 of STA2 intercepted and captured this ACF signaling, behind the ASN.1 decoder decode, had obtained H.225 calling out the IP address (STA2) and the transport layer port 1720 of control channel.Therefore the H.225 CallSignaling link information table in the IP speech link information storehouse on the MAP1 has obtained renewal, and it thes contents are as follows:
| Sequence number | The IP address | Port |
| 1 | STA2 | 1720 |
STA1 receives after this ACF, sends one through CallSignaling channel H.225 to STA2 and connects and set up (SETUP) message.STA2 accepts this and calls out, and keeps the signaling exchange that server Portal carries out ARQ/ACF with H.323 closing earlier, replys to STA1 then to connect (Connect) message.
In above-mentioned signalling interactive process; MAP1 intercepts and captures earlier the SETUP signaling message that STA1 sends, and after decoding, obtains later stage used IP address and the transport layer port of medium control protocol H.245; And upgrade in the IP speech link information storehouse and H.245 show, it thes contents are as follows
| Sequence number | The IP address | Port |
| 1 | STA1 | 1350 |
And gateway node Portal has intercepted and captured the ACF message that mails to STA2; After decoding; Obtained the IP address and the tcp port of the Call Signaling channel H.225 of STA1, and upgraded the H.225 Call Signaling table in the IP speech link information storehouse, theed contents are as follows
| Sequence number | The IP address | Port |
| 1 | STA1 | 1720 |
Next; Because the information of the H.225 CallSignaling signalling path of STA1 has been arranged; Be hunted down so mail to connection (CONNECT) message of STA1, after the decoding, the later stage that obtains STA2 is the tcp port of the used IP address of medium control channel H.245; So the IP speech link information table in the gateway node obtains upgrading, it thes contents are as follows:
| Sequence number | The IP address | Port |
| 1 | STA1 | 1350 |
STA1 and STA2 utilize the H.245 channel of being opened to carry out media communication then, because the H.245 information of channel has all been arranged on MAP1 and gateway node Portal, so can intercept and capture these Signalling exchanges.In these signalings, the most important thing is to open logical channel (openLogicChannel) signaling and open logical channel affirmation signaling (openLogicChannelAck), they have specified last IP Speech Communication used IP address and transport layer port.Be that MAP1 has intercepted and captured STA1 and sends out the signaling to the openLogicChannel of STA2, after decoding, obtained the IP address of the used transport layer port of Speech Communication and STA2, upgrade the central Speech Communication information table in IP speech link information storehouse, it thes contents are as follows:
| Sequence number | The IP address | Port |
| 1 | STA2 | 49156 |
| Gateway node Portal has intercepted and captured STA2 send out to the openLogicChannelAck of STA1 signaling, after decoding, has obtained the IP ground of Speech Communication transport layer port and STA1 | The IP address | Port |
| Speech Communication information table in the middle of the IP speech link information storehouse is upgraded in the location, and it thes contents are as follows: sequence number | ? | ? |
| 1 | STA1 | 49152 |
Through after the above-mentioned steps, in the qos policy traffic identification the information that will use ready.
Next be that the communication process of IP speech: MAP1 extracts all communications packets at transport layer 49156 ports, enter the IP speech buffer queue of oneself; Gateway node extracts all communications packets at transport layer 49152 ports, enters the IP speech buffer queue of oneself.
Like this, after the IP voice service is distinguished, be placed into an independent buffer queue; Other business is that Best-Effort service then is placed into the another one buffer queue; Because hypothetical network is in congestion state, so the formation of Best-Effort service all approaches full at any time.Suppose the G.721 speech coding scheme that the IP voice service adopts again, so the MP-MLQ coding standard of basis defined G.723, the every 30ms of IP voice service buffer queue just has a 200bit Frame to get into formation.
In this example, adopt ratio probabilistic dispatching algorithm, the configuration of IP voice queue occupies 10% sending probability; Best-Effort service occupies 90% sending probability, and the physical layer transmission rate of establishing this moment is 54Mbps, and by experiment gained data; This moment is under the situation of MAP1 and gateway node Portal double bounce; The 10Mbps of the speed end to end of two IP voice terminals supposes average data Bao Changwei 1000bits, then each second 10000 times send opportunity can be provided.At this moment, the process of transmitting of buffer queue is following:
Produce one (0,1) interval random number x, if 0＜x＜0.1, and the IP voice queue obtains send opportunity, if 0.1＜x＜1, then Best-Effort service obtains send opportunity.
According to above-mentioned analysis, when the formation of IP voice service obtains send opportunity,, will abandon current send opportunity if formation this moment does not have Frame, if Frame is arranged, will obtain immediately sending.Because single IP speech connection needs per 30 milliseconds of send opportunity once; Be equivalent to the general 33 times send opportunity of per second kind needs; Be significantly smaller than the send opportunity that formation offers its per second 1000 times, the service quality of IP speech (QoS) can be met fully.
Claims (7)
1. car ground broadband access method based on wireless multi-hop network technology is by the radio node of vehicle-mounted subnet, insert public internet network through wireless multi-hop networks again; Wherein wireless multi-hop networks is made up of a plurality of wireless multi-hop nodes; The wireless multi-hop node is gateway node or access node, and access node has a plurality of, and the employed protocol stack of wireless multi-hop networks has the 1st, 2 layer IEEE 802.11g agreement; The 3rd layer IP agreement; It is characterized in that: also have the 2.5th layer protocol based on layer 2 address between described the 2nd, 3 layer protocols, the 2.5th layer protocol has been stipulated the cut-in method of wireless multi-hop node, and this cut-in method is made up of following steps:
A, each wireless multi-hop node generate or upgrade the routing table of tree type, write down the father of this wireless multi-hop node, the physical address of child node; And establishment proxy table; This proxy table comprises the list item of all the vehicle-mounted subnet nodes below this wireless multi-hop node tree type route, and each list item is made up of the physical address of the physical address of this wireless multi-hop node, vehicle-mounted subnet node that this wireless multi-hop node is acted on behalf of; The physical address of the vehicle-mounted subnet node of perhaps being acted on behalf of by the physical address of the child node of this wireless multi-hop node, this child node and with lower node is formed;
The transmission of B, Frame: the wireless multi-hop node combines the inquiry of proxy table, routing table simultaneously through routing algorithm; Confirm routed path; Call transmission, reception, retransmission process again, realize between the wireless multi-hop node, the data between wireless multi-hop networks and the vehicle-mounted subnet, between wireless multi-hop gateway node and the public internet send, receive and forwarding; And between wireless multi-hop networks and vehicle-mounted subnet, between wireless multi-hop gateway node and the public internet, carry out format conversion during the transmission data; The concrete grammar of said format conversion is: between the Frame frame head of the 2nd layer data frame frame head and the 3rd layer, add the 2.5th layer wireless multi-hop frame head, each field of this wireless multi-hop frame head is followed successively by: next jumps physical address, last a jumping physical address, target physical address, source physical address, wireless multi-hop frame type field, business type field in the Frame;
The switching of C, node: the access channel of all wireless multi-hop nodes all adopts the channel of same frequency; Vehicle-mounted subnet node is surveyed the reception signal strength signal intensity of other wireless multi-hop nodes at any time; When the received power value of the wireless multi-hop node that is using is lower than predetermined threshold value; And when the received power value that detects new wireless multi-hop node is higher than this threshold value, when keeping old connection, initiate connection request to new wireless multi-hop node; After requested node is received request signal, the update agent table, foundation is connected with this vehicle-mounted subnet, and old connection is broken off in vehicle-mounted then subnet request, breaks off it by old node and connects and update agent table.
2. a kind of car ground broadband access method based on wireless multi-hop network technology as claimed in claim 1 is characterized in that the addressing method of the transmission of described Frame is:
Addressing when sending data: when sending data, at first search proxy table,, then Frame is sent to wireless multi-hop node processing corresponding in the proxy table if there is the physical address of the vehicle-mounted subnet node of purpose in the proxy table; If do not exist, then send to father node and handle;
Addressing when reception and forwarding data: after receiving data, search routing table, if there is not a last jumping address of this Frame in the routing table, then confirm it is not the Frame that own father node and child node are sent, this Frame abandons; If receive the Ethernet broadcast data frame, then handle by the layer 3 network agreement, and send to all nodes of removing in the routing table beyond the broadcast data frame source node simultaneously by this node; If receive the Ethernet unicast data frames, search proxy table, if self be the agent node of this Frame Ethernet destination address; Then handle by the layer 3 network agreement by this node; Otherwise, carrying out forwarding of data, the addressing method of data forwarding is identical with the transmission Frame.
3. a kind of car ground broadband access method based on wireless multi-hop network technology as claimed in claim 1 is characterized in that: described the 2.5th layer protocol also comprises the 2nd layer of IP voice service method for guaranteeing quality, and this method may further comprise the steps:
At the access or the gateway node of wireless multi-hop network, Frame is discerned and the IP voice data frame that identifies is carried out mark, promptly in the business type field of the wireless multi-hop frame head of Frame, be recorded as speech; In the repeating process of Frame, the preferential forwarding has the voice data frame.
4. a kind of car ground broadband access method based on wireless multi-hop network technology as claimed in claim 3 is characterized in that: described Frame is discerned and to the method that the IP voice data frame that identifies carries out mark is:
A1, the 2nd layer of IP speech signaling are caught: from Frame, obtain to set up or remove the signaling that the IP speech connects period;
A2, IP speech signaling resolve: as the signaling that is resolved to be the signaling that connects, and connection IP address, transport layer port information with the IP speech of acquisition deposit IP speech link information storehouse in; As the signaling that is resolved to is for removing signaling, then with corresponding connection IP address, transport layer port information deletion in the link information storehouse;
A3, the recognition methods of IP voice service: the information in purpose IP address in the IP frame head in the Frame frame head that on the 2nd layer, all is passed through and the destination interface in the transport layer frame head and the IP speech link information storehouse compares; If have this IP address and corresponding port in the information bank, then this Frame be labeled as the voice data frame.
5. a kind of car ground broadband access method based on wireless multi-hop network technology as claimed in claim 4 is characterized in that: the concrete grammar that the 2nd layer of IP speech signaling caught in the described A1 step is:
All Frames are made a copy, from copy, take out the IP frame head of Frame and the transport layer header of transport layer, obtain wherein source IP address, purpose IP address, source port, destination interface; And confirm that according to this its type of message is: H.225 authentication registration state (RAS) message of agreement, call-signaling message H.225, H.245 control a kind of in signaling message, conversation initialized protocol (SIP) protocol message; According to the type of message that obtains, call the IP speech signaling analytic method in the A2 step; Otherwise abandon this Frame copy.
6. a kind of car ground broadband access method based on wireless multi-hop network technology as claimed in claim 4 is characterized in that: the concrete practice that IP speech signaling is resolved in the described A2 step is:
H.225 authentication registration state (RAS) message of agreement is decoded with ASN.1 coding standard decoder; To H.225 call-signaling message or H.245 control the signaling that the connection in the signaling message sets up and remove and decode with ASN.1 coding standard decoder; Signaling to the connection of conversation initialized protocol (SIP) protocol message is set up and removed is decoded with the text protocol decoder.
7. a kind of car ground broadband access method as claimed in claim 4 based on wireless multi-hop network technology; It is characterized in that; Described IP speech link information storehouse; Comprise following three information tables: authentication registration state (RAS) link information table H.225, each list item of this table comprises the IP address and the transport layer port of an authentication registration state (RAS) transmission channel; H.225 call signaling link information table, each list item of this table comprises the IP address and the transport layer port of a call signaling transmission channel; Speech Communication link information table, each list item of this table comprises the IP address and the transport layer port of the transmission that the Speech Communication agreement of an IP speech and video communication is used.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008100449481A CN101237470B (en) | 2008-03-11 | 2008-03-11 | A car ground broadband access method based on wireless multi-hop network technology |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008100449481A CN101237470B (en) | 2008-03-11 | 2008-03-11 | A car ground broadband access method based on wireless multi-hop network technology |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101237470A CN101237470A (en) | 2008-08-06 |
| CN101237470B true CN101237470B (en) | 2012-01-25 |
Family
ID=39920827
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2008100449481A Expired - Fee Related CN101237470B (en) | 2008-03-11 | 2008-03-11 | A car ground broadband access method based on wireless multi-hop network technology |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101237470B (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5380023B2 (en) * | 2008-09-16 | 2014-01-08 | 日立コンシューマエレクトロニクス株式会社 | Wireless video transmission device, wireless video reception device, wireless communication system, and message transmission method |
| CN101447826B (en) * | 2008-12-26 | 2012-10-03 | 华为技术有限公司 | Subframe allocation method, processing method and device thereof |
| CN101827416A (en) * | 2010-04-02 | 2010-09-08 | 华为技术有限公司 | Node switching method in wireless sensor network, network and network node |
| CN101888679B (en) * | 2010-05-31 | 2012-08-22 | 西南交通大学 | Multi-vehicle mounted station cooperation cell switching method for train-ground communication under high-speed moving environment |
| CN101951691B (en) * | 2010-09-19 | 2014-03-12 | 中兴通讯股份有限公司 | Wireless hot spot sharing and accessing method and device |
| KR101798052B1 (en) * | 2011-04-26 | 2017-11-15 | 현대모비스 주식회사 | Teminal for vehicle and communication method using the theminal |
| CN102722377B (en) * | 2012-06-28 | 2015-05-20 | 上海美琦浦悦通讯科技有限公司 | Network video application processing system based on adaptive communication environment (ACE) framework |
| CN102857918A (en) * | 2012-10-12 | 2013-01-02 | 北京汽车股份有限公司 | Vehicle-mounted communication system |
| CN103220745A (en) * | 2013-04-18 | 2013-07-24 | 上海桑锐电子科技有限公司 | Wireless network route method |
| CN104333467B (en) * | 2014-11-05 | 2017-11-24 | 福建星网锐捷网络有限公司 | A kind of gateway proxy method and apparatus of track traffic wireless network links failure |
| CN106993033B (en) * | 2017-03-28 | 2020-02-14 | 北京汽车股份有限公司 | Vehicle-mounted Ethernet system based on ad hoc network and vehicle with same |
| CN107018200A (en) * | 2017-04-20 | 2017-08-04 | 中南大学 | A kind of high-speed rail mobile communication system and method |
| CN108135021B (en) * | 2017-11-17 | 2020-04-14 | 浙江大学 | Communication method for sharing transportation means under scene without direct network |
| CN111107568B (en) * | 2018-10-25 | 2022-09-27 | 成都鼎桥通信技术有限公司 | Distributed networking method, system, equipment and storage medium for multi-hop relay |
| CN111245727B (en) * | 2020-01-07 | 2022-08-12 | 深圳市网心科技有限公司 | Message routing method, electronic device, proxy node and medium based on DHT network |
| CN113347645A (en) * | 2021-05-28 | 2021-09-03 | 刘秀萍 | 802.11 wireless multi-hop communication and self-adaptive switching method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1011241A1 (en) * | 1998-12-11 | 2000-06-21 | Lucent Technologies Inc. | Wireless access to packet-based networks |
| CN1842207A (en) * | 2005-03-31 | 2006-10-04 | 西门子（中国）有限公司 | Distributed multihop wireless network access method |
| CN1959758A (en) * | 2006-11-24 | 2007-05-09 | 清华大学 | Intellective traffic information system based on mobile mesh network |
-
2008
- 2008-03-11 CN CN2008100449481A patent/CN101237470B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1011241A1 (en) * | 1998-12-11 | 2000-06-21 | Lucent Technologies Inc. | Wireless access to packet-based networks |
| CN1842207A (en) * | 2005-03-31 | 2006-10-04 | 西门子（中国）有限公司 | Distributed multihop wireless network access method |
| CN1959758A (en) * | 2006-11-24 | 2007-05-09 | 清华大学 | Intellective traffic information system based on mobile mesh network |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101237470A (en) | 2008-08-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101237470B (en) | A car ground broadband access method based on wireless multi-hop network technology | |
| CN1656834B (en) | Flow-based selective reverse tunneling in wireless local area network (WLAN)-cellular systems | |
| AU2003248437B2 (en) | Packet Transmission System and Packet Reception System | |
| CN103685023B (en) | Broadband satellite communication system and method based on satellite-borne IP switching | |
| US8780770B2 (en) | Systems and methods for voice and video communication over a wireless network | |
| JP4715521B2 (en) | Communication system and call control server | |
| US8169984B2 (en) | Communication system, radio lan base station control device, and radio lan base station device | |
| US20090279701A1 (en) | Controlling access nodes with network transport devices within wireless mobile networks | |
| US8767692B2 (en) | Communication method in an IEEE 802.11 wireless LAN environment | |
| JP2009509414A (en) | Method for improving capacity in multi-hop wireless mesh networks | |
| CN101651963B (en) | Transmission control method based on differentiated service in IEEE 802.11 WLAN | |
| WO2005107161A1 (en) | A system and communication method of ip telecommunication network and its application | |
| Tu et al. | Resource-aware video multicasting via access gateways in wireless mesh networks | |
| CN102104538A (en) | Mapping parameter dynamic adaptive wireless streaming media transmission control method | |
| WO2019183919A1 (en) | Method and apparatus for converged networking | |
| CN100531152C (en) | Equipment, system and realizing method for wireless local network transmission group broadcasting frame | |
| CN116233256A (en) | Scheduling path configuration method, device, equipment and storage medium | |
| US7379443B2 (en) | Method of dynamic management of a virtual local area network (VLAN) in a wireless ad hoc network | |
| CN102170389A (en) | Transmission method and access device for data message | |
| US8488607B2 (en) | Method for WLAN link aggregation and system for using the same | |
| JP2000224216A (en) | Repeater, communication terminal and communication method | |
| CN110601893B (en) | Data transmission system, method and device | |
| Brahma et al. | A load-balancing and push-out scheme for supporting QOS in MANETs | |
| De et al. | On throughput and load balancing of multipath routing in wireless networks | |
| CN109873723A (en) | Bandwidth on-demand distribution method based on node traffic priority |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120125 Termination date: 20150311 |
|
| EXPY | Termination of patent right or utility model |